Mechanical rotary self-interlocking device



Feb. 13, 1968 A. STRATIENKO 3, v

MECHANICAL ROTARY SELF-INTERLOCKING DEVICE Original Filed June 25, 19622 sheets-sheet 1 Feb. 13, 1968 I A. STRATIENKO ,3

MECHANICAL ROTARY SELF-INTERLOCKING DEVICE Original Filed June 25, 1962v 2 Sheets-Sheet 2 'INVEN Andrew Jfra eg/f0 ATTORN EY6 United StatesPatent 3,368,834 MECHANICAL ROTARY SELF-INTER- LOCKING DEVICE AndrewStratienko, 5139 N. 15th, Philadelphia, Pa. 19141 Continuation ofapplication Ser. No. 204,918, June 25, 1962. This application Nov. 14,1966, Ser. No. 594,265 4 Claims. (Cl. 28752.09)

This application is a continuation of application Ser. No. 204,918,filed June 25, 1962, and now abandoned.

The present invention relates to a rotary self-interlocking wedgedevice.

When reference is made herein to the inclined Wedge surfaces as beingcylindrical it should be kept in mind that they are curved surfaceswhose section is a circle but that they may be right cylindricalsiirfaces or conical surfaces.

A purpose of the invention is to provide a rotary selfinterlocking wedgedevice, comprising a shaft member, a hub member surrounding the shaftmember and having a space of annular section between the shaft memberand the hub member, the members being relatively rotatable about thecommon axis of the shaft member and the hub member, with pairs ofcooperating wedges interposed in the said annular space on the opposedsides, each pair of wedges comprising a radially inner wedge having aradially inner cylindrical surface coaxial with said common axis andcooperating with the outer cylindrical surface of said shaft member, andhaving a radially outer cylindrical inclined wedge surface, andcomprising a radially outer wedge having a radially inner cylindricalinclined wedge surface of the same radial offset as the radially outerinclined wedge surface on the inner wedge of the pair, the inclinedWedge surface of the outer wedge of each pair engaging and cooperatingwith the inclined wedge surface of the inner wedge of the same pair, andthere being permanent anti-friction means effective on one of saidinclined Wedge surfaces, and the radially outer wedge of each pairhaving a radially outer cylindrical surface coaxial with said commonaxis and cooperating with the inner cylindrical surface of said hubmember, each of the said pairs of wedges which have the same directionof inclination of the inclined wedge surfaces relatively tightening whenrotation is in the direction toward inclination of the inclined wedgesurfaces and each of said pairs of wedges which have the same directionof inclination of the inclined wedge surfaces relatively loosening whenthe rotation is in the direction away from the inclination of theinclined wedge surfaces, said wedge device complying with the followingconditions:

where f is the coeflicient of sliding starting friction on the coaxialcylindrical surfaces of said inner wedges,

f is the coflicient of sliding starting friction on the coaxialcylindrical surfaces of said outer wedges a is the radial offset fromthe axis of the center of said cylindrical inclined wedge surfaces.

,u is the coeificient of sliding friction on said curved inclined wedgesurfaces,

r is the radius of curvature of said inner cylindrical coaxial wedgesurfaces,

r is the radius of curvature of said outer cylindrical coaxial wedgesurfaces,

r is the mean radius of curvature of said cylindrical inclined wedgesurfaces in respect to the axis of hub rotation,

whereby said wedges produce a self-interlocking action at said externaland internal cylindrical coaxial surfaces in the direction of rotationtoward the inclination of the inclined wedge surfaces.

A further purpose is to employ at suitable intervals; around thecircumference oppositely directed pairs of inner and outer wedges, sothat in the direction of motion in which the wedges referred to aboveloosen, these oppositely directed wedges tighten, and vice versa.

A further purpose is to provide a permanent and stable slidinganti-friction means on the co-operating cylindrical inclined wedgesurfaces of said wedges.

A further purpose is to provide pre-engaging means for producing limitedmovement of outer Wedges of opposed pairs in relation to inner wedges ofsaid opposed pairs in a direction toward the inclination of the inclinedwedge surfaces for pre-tightening the wedge elements against theconcentric surfaces of the hub and shaft members.

A further purpose is to provide disengagement means for producinglimited relative movement of outer and inner wedges in a direction awayfrom the inclination of the wedge surfaces for loosening of wedgeelements in an annular space between hub and shaft members.

A further purpose is to provide flanges on the wedges and to producelimited relative motion of the flange connected to the outer wedge ofone pair away from the flange connected to the inner wedge of theopposed pair.

A further purpose is to provide also on the wedges inclined wedgesurfaces when viewed in axial section.

A further purpose is to provide positive means for moving the wedges ofsaid pairs relatively axially to tighten or loosen.

A further purpose is to make self-interlocking wedges alsoself-releasing by making the device comply with the expression a r t,the terms being as defined above.

A further purpose is to pre-engage on the cylindrical surface of thewedge in either static or dynamic wedge devices.

A further purpose is to provide spring action between the opposed wedgessuitably from the outer wedge of one pair to the inner wedge of theopposed pair.

A further purpose in the case of tire-engaging and disengaging is toprovide a resilient mechanism, such as a spring, to transfer motion fromouter wedges to inner wedges in the direction toward or away from thedirection of inclination (tightening or loosening, as the case may be).

A further purpose is to utilize the invention in rotaryself-interlocking rings.

A further purpose is to provide means for disengaging the wedges as byapplying force from one wedge of one pair to another wedge of anotherpair.

A further purpose is to utilize the invention in a manually orautomatically adjusted sliding bearing.

A further purpose in a rotary self-interlocking ring is to transmittorque between the hub and the shaft which will have ability to grip andpositively interlock between two smooth cylindrical surfaces withoutrequiring machining of slots, holes, flats or other provisions forlocking elements such as keys, pins, set screws or the like.

A further purpose is to provide both rotational and axial locking effectin a self-interlocking rotary thrust ring.

A further purpose in a manually adjusted sliding bearing is to lock thedevice to take up wear and adjust clearance between the shaft and thebearing in both directions of rotation.

A further purpose is to automatically comperfsate for wear in a slidingbearing.

A further purpose is to fabricate wedge elements as eccentrics and thenseparate them to form wedges and reverse them to apply the principles ofthe present invention.

A further purpose is to make either the inner or the outer wedges as thecase may be, integral with or to fix them to the adjoining member, whichis the shaft in the case of the inner wedges or the hub member in thecase of the outer wedges, while maintaining the above relationship asfar as it is appropriate to the particular device.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate a few only of the numerousembodiments, selecting the forms shown from the standpoints ofconvenience in illustration, satisfactory operation and cleardemonstration of the principles involved.

FIGURE 1 is a diagrammatic end elevation of a device of the inventionshowing two reverse pairs of rotary wedges in opposed relation, theouter circle suggesting the bore of the member which is not separatelyillustrated.

FIGURE 2 is a diagrammatic elevation of the assemblage of componentsfrom which the reverse pairs of rotary wedges of the invention are to bemade, showing the offset of the center of the eccentric surfaces whichis later described.

FIGURE 3 is a view similar to FIGURE 1, showing three pairs of reversewedges completing the circumference of the device.

FIGURE 4 is an axial section of a rotary self-interlocking ringaccording to the invention, the section being taken on the line 4-4 ofFIGURE 5.

FIGURE 5 is an end elevation partly in transverse section on the line5-5 of FIGURE 4, omitting the hub member.

FIGURE 6 is an axial section of a torque thrust selfinterlocking ring ofthe invention, the section being taken on the line 6-6 of FIGURE 7.

FIGURE 7 is a transverse section of the device of FIGURE 6 on the line7-7 of FIGURE 6 omitting the hub member.

FIGURE 8 is an axial section taken on the line 8-8 of FIGURE 10, showingan automatically adjustable sliding bearing of the invention with fixedinner wedges on the shaft.

FIGURE 9 is a section of FIGURE 8 on the line 9-9.

FIGURE 10 is a section of FIGURE 8 on the line 10-10.

FIGURE 11 is a fragmentary plan section of the device of FIGURE 8 on theline 11-11.

FIGURE 12 is an axial section of an automatically adjustable slidingbearing of the invention with the outer wedges fixed in the bore of thehub member as by an interference fit so that they are effectivelyintegral with the hub member.

FIGURE 13 is a section on the line 13-13 of FIG- URE 12.

FIGURE 14 is an axial section taken on the line 14-14 of FIGURE 16 of amanually adjustable sliding bearing according to the invention locatedfor rotation in both ways with tixed inner wedges on the shaft which areeffectively integral with the shaft from the standpoint of operation.

4 FIGURE 15 is a section on the line 15-15 of FIG- URE 14.

FIGURE 16 is a section on the line 16-16 of FIG- URE 14.

In various sections the hub member has been omitted to conserve space.

FIGURE 17 is an axial section on the line 17-17 of FIGURE 18 through amanually adjustable sliding hearing of the invention locked for rotationin both ways with wedges which are effectively fixed at the outside asdue to interference fit in the bore of the hub member.

FIGURE 18 is a section on the line 18-18 of FIG- URE 17.

Describing in illustration but not in limitation and referring to thedrawings:

The present invention relates to opposed wedge devices which have theability to self-interlock in one direction of rotation and which in thepreferred embodiment also have the ability to self-release in some casesin the other direction of rotation.

Considering FIGURE 1 as an example, I there show a shaft 40 which issuitably a conventional shaft having a right circular cylindrical outersurface 41 and coaxial thereto an axis 42. Of course, while the shafthas been shown as a solid shaft, it may be tubular in someinstallations.

The shaft is surrounded in spaced relation with a hub member 43 whichhas an internal bore 44 coaxial with the common axis of the shaft andbore of the hub member. While this hub member has been thus generallydesignated, it will be evident that in many cases it will take the formof a machine part or element which is being mounted on or used inconnection with the shaft, such as a gear, cam, lever, inner bearingmember or the clutch member, as well known in the art.

Interposed between the hub member and the shaft in the concentric spacebetween the two are opposed pairs of wedges. Each pair includes an innerwedge 45 which has at the radial inner surface which engages thecylindrical outer surface 41 of the shaft, an internal cylindricalsurface 46 coaxial with the common axis and of the same radius ofcurvature as the shaft. The inner cylindrical surface 46 of the innerwedge has no special treatment to reduce its coefficient of friction,but suitably may be simply a machined surface which is engagedmetaltometal with the outer surface of the shaft. In this case forexample, where both the shaft and the wedges are of steel, the innersurface 46 will simply be a steel machined surface in the preferredembodiment. In some cases the inner surface 46 and permissibly in thatcase also the outer cylindrical surface 41 of the shaft may beartificially roughened as by knurling or otherwise. This, however, isordinarily not necessary and in many cases is not desirable.

The inner wedges 45 also have radially outer cylindrical inclinedsurfaces 47 which are eccentric with respect to the common axis. Thisconcept of the eccentric cylindrical inclined wedge surface at theradial outside of the inner wedge will be better understood by referenceto FIGURE 2 in which the manufacture of the wedges is shown. In thisinstance it will be evident that the surface of the shaft 41 issurrounded by a ring 48 which has an inner surface 46 which just fitsover the shaft and is cylindrical and of substantially the same diameteras the shaft.

Let us assume for the sake of understanding that the ring 48 is severedby an eccentric cut 50 of theoretically zero width which is circular asshown but is on an eccentric axis 51 which has an offset 52 from thecommon axis 42. Then initially the ring 48 is separated into an innereccentric ring portion 53 and an outer eccentric ring portion 54. Nowlet us suppose that the inner ring portion 53 is separated by cutting itapart radially at 55 and also at a diametrically opposite position isseparated by making two adjoining substantially radial cuts 56 and 57.Also the outer ring portion 54 is cut apart radially at 58 and at adiametrically opposite position is severed by two substantially radialadjoining cuts 60 and 61. Actually eccentric rings 53 and 54 will bemade to fit together as shown. It will be evident then that two innerwedges 45 are formed of the character which we have just been describingand also two outer wedges 62 which will later be described. Of course,it will be evident that while this offers one means of generating theinner and outer wedges as desired for the invention, any other manner ofgenerating wedges of similar shape can be used as will be evident toothers skilled in the machining art.

The outer inclined cylindrical but offset or eccentric surface 47 of theinner wedges in the preferred embodiment of the invention will either beprovided with an anti-friction surface such as an anti-friction shoe orcoating. In the case of the coating, as well known, it may be a bondedlayer of polytetrafluoroethylene (Teflon), a bonded layer of molybdenumsulfide, a coating as by plating with chromium, or silver, or it mayhave shoes of anti'friction material such as bronze, or powdered metalimpregnated with suitable lubricant, such as graphite, or silver-indium,babbit, lead base alloys, or hardening the surfaces, suitably usingbetween them a thin layer of soft material, like indium or the like.These produce permanent anti-friction means on an inclined wedgesurface. Any other well known method for decreasing friction oneccentric surfaces may be employed. Returning now to the description ofFIGURE 1, it will be noted that the inner wedges 45 as generated inFIGURE 2 have been reversed with respect to one another so that theywill both relatively tighten and both relatively loosen in the samedirection of rotation when applied to FIGURE 1.

The wedges are arranged in pairs and the outer wedges 62 have innercylindrical eccentric wedge surfaces 63 whichare of the same offset asthe outer surfaces 47 on the inner wedges and which fully cooperatethroughout their length with the corresponding outer surfaces on theinner wedges. This surface 63 on each outer wedge likewise in thepreferred embodiment may have anti-frictional material of the characterjust described so that it will have a low coetficient of frictionagainst the inner wedge surface 47. Each outer wedge at the radial outersurface has a cylindrical coaxial surface 64 which in the preferredembodiment is not of low coefficient of friction but is of the sameradius of curvature and engages and cooperates with the inner rightcylindrical surface 44 on the hub member. In some embodiments the outersurface of the outer wedges may be roughened as by knurling or the likeand the corresponding bore of the hub member may similarly be roughenedthough for example where the hub member and also the outer wedge are ofsteel, ordinary steel on steel engagement without roughening will innormal operation produce a sufliciently high coefficient of friction aslater explained.

Reference has been made in various places to the pairs of wedges beingopposed. This does not necessarily mean that one pair of wedges must bediametrically opposite to another pair of wedges but it does mean thatthey must be opposite and cooperate. Thus in FIGURE 3 three pairs ofwedges divide the circumference and each pair of wedges is opposed bytwo opposite pairs of wedges in this case.

The invention is particularly concerned with the ability of the deviceto self-interlock and in certain cases, the ability of the wedge deviceto self-release.

Considering the device of FIGURE 1, in the best embodiment of theinvention, the following relations will exist for self-interlocking:

where f is the coefficient of sliding starting friction on the coaxialcylindrical surfaces of said inner wedges,

f is the coeflicient of sliding starting friction on the coaxialcylindrical surfaces of said outer wedges,

a is the radial offset from the axis of the center of said cylindricalinclined wedge surfaces,

,u is the coefficient of friction on said cylindrical inclined wedgesurfaces,

r is the radius of curvature of said inner cylindrical coaxial wedgesurfaces,

r is the radius of curvature of said outer cylindrical coaxial wedgesurfaces,

r is the radius of curvature of said cylindrical inclined wedge surfacesin respect to the common axis of rotation.

This device will give a self-interlocking action on the inside as shownby the first expression above and a selfinterlocking action on theoutside as shown by the second expression above.

The device will also self-release when a larger amount of radial offseta is used in inches than the product of the coeflicient of startingfriction on the inclined surface a multiplied by the radius of theinclined wedge surface in inches r.

Because of the considerations of stress and strain, it is desirable touse the highest possible amount of radial offset a within the limits forthe condition of self-interlocking.

The ratio between the amount of radial offset a and the product ,UJ'creates a factor of safety of self-releasing.

The ratio between the coeflicient of starting friction, and the productxt wo creates a factor of reliability for self-interlocking and thisdetermines the dependability of self-interlocking. It will be evidentthat the use of a device in which there is an extremely low coeflicientof starting friction on the inclined wedge surfaces is very important.The expedients as mentioned above for reducing this starting frictionare desirable.

In self-interlocking rings which do not have appreciable relativemovement between the parts and are therefore more nearly static, theconcentric cylindrical surfaces are not subjected to pronounced wear. Insuch devices the frictional coeflicient on the concentric surfaces 1 andthe radial offset a is limited by other conditions.

The invention will be better understood by reference to the remainingfigures of the drawings.

FIGURES 4 and 5 show the invention applied to a rotary self-interlockingring. The inner wedge of one pair has a semi-cylindrical flange appliedto it beyond the hub member 43 so as to form a shoulder 66, retainingthe hub member axially. The outer wedge of the opposite pair has asimilar semi-cylindrical flange 65' which fills the rest of thecircumference. This provides preengaging and disengaging features asapplied to a rotary self-interlocking ring, because the flange half 65from the inner Wedge of one pair is interconnected to the flange half65' of the outer wedge of the opposed pair by pre-engaging bolt 67connecting the opposite flange halves at one side.

Before further discussing the structure of FIGURE 5, it may be helpfulto understand pre-engagement and disengagement more fully.

The function of the pre-engagement feature is to produce limitedmovement of the outer wedges of the opposed pairs in relation to theinner wedges of the opposed pairs in the direction toward theinclination of the inclined wedge surfaces (that is the direction oftightening) for pre-tightening the wedge elements in the annular spacebetween hub member and the shaft member.

The function of the disengagement feature is to cause limited movementof all outer wedges of the opposed pairs in relation to all inner wedgesof the opposed pairs in the direction away from the inclination of theinclined surfaces to permit loosening of the wedge elements in theannular space between the hub member and the shaft member.

The function of pre-engagement in rotary devices is achieved byspreading apart (moving away) the thick ends of the outer wedges and thethick ends of the inner wedges of adjacent pairs, by using rigidexpandible members between the thick end of the outer wedge of the onepair and the thick end of the inner wedge of the other pair, as is doneby the jackscrew 72' in FIGURES 16 and 18, later to be described, or asis done by springs 71. in FIGURES 8 and 11 later to be described. Thesame purpose is achieved by tightening together (moving toward oneanother) the thin ends of the outer and inner wedges of the adjacentpairs using rigid or resilient pretightening means interconnecting thethin end of the outer wedge of the first pair and the thin end of theinner wedge of the last pair as has been just described, by means ofpre-tightening bolt 67 of FIGURE 5.

With this general discussion of the functioning of preengaging anddisengaging, we can now turn to the further discussion of FIGURE 5. Thefunction of disengagement (which is used for rotary self-interlockingcollars which do not have the propeitly of self-releasing) is achievedby spreading apart the thin ends of the outer wedges and the thin endsof the inner wedges of adjacent pairs opposite to pre-engaging.

The same purpose is achieved by moving toward one another the thick endof the outer wedge and the thick end of the inner wedge of each adjacentpair by means of the pre-engaging bolt 67 in FIGURE 5 which reallyfunctions as a disengaging screw. Like screw 67, screw 67 extends acrosstangentially from one flange half 65 to the opposite flange half 65 asthey are shown.

In rotary-trust rings the function of pre-engaging and disengaging isachieved by an axial taper and by the preengaging nut 70 later to bedescribed in connection with FIGURE 6, and which achieves the samepurpose as above mentioned.

FIGURES 6 and 7 show inner and outer wedges 45' and 62' which havewedge-like engaging surfaces as viewed transverse to the axis in FIGURE7 and also wedge-like surface engaged with one another when viewedaxially in FIGURE 6. Thus the cooperating surfaces in this instance aredesignated as 47 and 63, and they meet the requirements of surfaces 47and 63 as already described and also cooperate axially as wedges asshown in FIGURE 6. To obtain the pre-engaging and disengaging in thiscase, the inner wedge elements have external semi-cylindrical threads 68concentric with the axis and these cooperate to receive a nut 70 whichwhen screwed up urges the outside wedges 62 axially to tighten and whichwhen loosened, permits these wedges to loosen. This device is describedas a torque thrust ring.

In the case of the self-interlocking rings of FIGURES 6 and 7, the axialtaper on the eccentric surface of the wedge has two functions. Onefunction is to retain axial thrust and the angle of inclination asviewed axially should be selected in accordance with the principles oflinear self-interlocking as disclosed in by copending application Ser.No. 197,770, filed May 25, 1962, for Linear Self Interlocking WedgeDevice, now abandoned. The second function is to enable the wedges topretighten in the annular space between the inner and outer member bymeans of the special pretightening nut which surrounds the internalmember and accomplishes pro-engagement. In this case, the angle of axialinclination may or may not be selected according to the principle oflinear self-interlocking or self-releasing, depending upon theparticular conditions, and may be chosen merely to pre-engage anddisengage.

The combination of left hand assembly with right hand self-interlockingcollars in the same installation is possible for transmitting torque orretaining thrust in both directions. This is possible for both rotaryrings and also for thrust torque rings.

Rotary wedges can also be pre-tightened using screw or other suitablemeans installed in or supported against any part, which may be fixed onthe driving or driven member of the machine as required.

The device of FIGURES 8 to ll may conveniently be used as anautomatically adjustable sliding bearing with inner fixed wedges. Theinner wedges in this device are effectively integral with the shaft andcould actually be made so if desired.

In automatically adjusting sliding bearings, leaf springs 71 act toadjust the clearance. Suitable pretightening screws 74 act between theflange halves 75 from the inner wedges of the opposite pairs forpre-tightening inner wedges on the shaft. At one end the high end innerwedge is limited in its movement towards the large end of the oppositeouter wedge by screw 72 which acts similarly to the pre-engaging screwpreviously described, but has the function of limiting and controllingclearance between the overrunning concentric surfaces and also suitablycompensating for wear. Setscrew 72 controls clearance between wedgeelements for achieving stability of the hub member in relation to theshaft when overrunning.

In the device of FIGURES 8 to 11 and similarly in other devices later tobe described, to limit axial relative motion of the wedges axial flangehalves 69 are provided at the opposite axial ends of the members havingthe flange halves 75.

Automatically adjustable sliding bearings of FIGURES 8 to 11 or ofFIGURES 12 and 13 have radial oflset a and the frictional coefficientson the eccentric and concentric surfaces of the wedges are chosen withcertain objectives in view. Where the bearing operates in a directiontending to tighten the wedges, the wedges are designed with a largeamount of radial offset to prevent self interlocking action and thepre-engaging spring 71 is sufficiently stiff to withstand self-releasingand loosening of wedges due to radial load on the bearings. Automaticcompensation of bearing clearance is accomplished by frictional drag onthe sliding surfaces.

In case the bearing operates in a direction which tends to loosen thewedges, spring force automatically compensates for bearing clearance,the wedges and the spring in this case being designed to withstandfrictional drag on the concentric sliding surfaces of the device, andthe device may be designed as desired so that it either will be or willnot be self-interlocking or self-releasing. The adjustable jackscrew 72is then used to adjust and to limit maximum clearance in the case wherethe frictional drag exceeds the spring force. In this case the bearingalso may operate without the spring used for the automatic compensationof bearing clearance. Bearing clearance may be controlled in thisinstance and compensation for wear may take place by means of thesetscrew 72. The setscrew 72 may also be used where desired to re-adjustthe spring force to suit operating conditions.

FIGURES 12 and 13 show a construction for an automatically adjustablebearing with the outer wedges fixed in the bore 44 of the hub member byan interference fit as will be seen in FIGURE 13 where the outer wedgesengage one another end to end. The shaft 40, therefore, comprises theoverrunning member in this case.

Jackscrew 72 limits the range of motion of one of the internal wedgeswith respect to an opposed external wedge and therefore controls theextent of relaxation of the internal wedge when the clutch isoverrunning. To provide pre-engaging of the wedges, spring 71 is used.

It will be noted in FIGRES l2 and 13 that flange halves appear at bothaxial ends of the device and limit axial movement, and the flange halvesin one case extend from the inner wedge and in the other case extendfrom the outer wedge as will be evident from FIGURE 12.

FIGURES 14, 15 and 16 illustrate a manually adjusting sliding bearingpositively locked for two directions of rotation and fixed with respectto the shaft. For decreasing the clearance in the sliding area of thebearings, the wedges must be unlocked by loosening attraction cap screw73 which interconnects the large end of one outer wedge to the large endof the opposite inner wedge. Additionally, one must engage the wedges tothe required extent by tightening jack set screw 72. This jackscrew 72'functions as a pre-engaging screw rather than limiting the range ofmotion as in the case of FIGURES and 13 which supports the thick ends ofan opposite outer wedge against an opposed inner wedge. For increasingthe clearance in the sliding area of the bearing, the wedges must beunlocked by loosening the jackscrew 72' and they must be disengaged tothe desired extent by tightening attraction cap screw 73. To have thebearing positively locked in both directions of rotation both theattraction cap screw 73 and the jackscrew 72' must be tightened oneagainst another to eliminate the effect of tightening or loosening ofwedges during operation.

In the form of FIGURES 14, 15 and 16, the fixation of the inner wedgeson the shaft is accomplished by cap screws 74 which connect opposedflanges 75 which in this case both come from inner wedges so that theinner wedges can be made to hug the shaft tightly.

Whereas the form of FIGURES 14, 15 and 16 is fixed on the shaft, theform of FIGURES 17 and 18 is similar but it is fixed in the bore 44 ofthe hub member 43. This is a manually adjustable sliding bearing lockedfor both directions of rotation. The fixation of the wedges in the bore44 of the hub member 43 is accomplished by an interference fit since theouter wedges engage one another end to end as shown in this form.

It will be evident that the self-interlocking devices of the inventionare built in such a way that the locking ability of the device isproduced by torque transmitted through the same device and the lockingcapacity is proportioned to the transmitted torque and always exceedsthe trans anitted torque. Therefore, the torque capacity of the deviceis limited only by the strength of the parts and is not limited by thegripping ability of the self-interlocking surfaces.

In operation of all of the devices previously described, it will beevident that where the inner and outer wedges are not locked, they willprovide self-interlocking in one direction of rotation and will in atleast some of the cases self-release in the other direction of rotation.By predetermining the position, the wedges can be made to preengage oneof the members. By controlling the limits of relative motion of thewedges, they can be made to form bearings, however, which may not beself-interlocking in either direction as previously explained.

Example 1 In this example, using the construction of FIGURES 4 and 5, apolytetrafluoroethylene (Teflon) coating was applied on the eccentricwedge surfaces and it gave a coefiicient of starting friction of 0.04 to0.05. This device Was tested and it gave successful performance withboth self-interlocking and self-releasing. The data and the calibrationare as follows:

1 equals coefiicient of sliding-starting friction between the shaft andthe concentric wedge surfaces equals 0.3,

r equals radius of the shaft equals 0.375 inch,

a equals amount of radial offset of eccentric wedge surfaces equals0.045 inch,

n equals starting coefiicient of sliding friction on eccentric wedgesurfaces equals 0.05,

r equals radius of eccentric wedge surfaces equal 0.451,

1 aw x (0040+ 0.05 0.451 0.181

The safety factor for self-interlocking is -=1.65 1 .1 1 ON-W) 0 8 Thesafety factor for self-releasing is In view of my invention anddisclosure, variations and modifications to meet individual whim orparticular need will doubtless become evident to others skilled in theart, to obtain all or part of the benefits of my invention withoutcopying the structure shown, and I, therefore, claim all such insofar asthey fall within the reasonable spirit and scope of my claims.

Having thus described my invention, what I claim as new and desire tosecure by Letter Patent is:

1. A rotary self-interlocking wedge device, comprising a shaft member, ahub member surrounding the shaft member and having a space of annularsection between the shaft member and the hub member, the members beingrelatively angularly movable about a common axis of the shaft member andthe hub member, pairs of cooperating wedges between the shaft member andthe hub member on opposite sides, each pair of wedges comprising aradially inner wedge having a radially inner cylindrical surface coaxialwith said common axis and cooperating with the outer cylindrical surfaceof said shaft member, and having a radially outer curved inclined wedgesurface whose section is circular and which is eccentric with respect tothe axis, and comprising a radially outer wedge having a radially innercurved inclined wedge surface whose section is circular and which iseccentric with respect to the axis and of the same radial offset as theradially outer inclined wedge surface of the inner wedge of the pair,the inclined wedge surface of the outer wedge of each pair being insliding frictional engagement with the inclined wedge surface of theinner wedge of the same pair, there being permanent antifriction meanson at least one of the inclined wedge surfaces which are in slidingengagement, and the radially outer wedge of each pair having a radiallyouter cylindrical surface coaxial with said common axis and cooperatingwith the inner cylindrical surface of said hub member, each of saidpairs of wedges which have the same direction of inclination of theinclined surfaces relatively tightening when rotation is in thedirection toward inclination of the inclined wedge surfaces and each ofsaid pairs of wedges which have said same direction of inclination ofthe inclined wedge surfaces relatively loosening when the rotation is inthe direction away from the inclination of the inclined wedge surfaces,said wedge device complying with the following conditions:

where f is the coeflicient of sliding starting friction on the coaxialcylindrical surface of said inner wedges, f; is the coeflicient ofsliding starting friction on the coaxial cylindrical surfaces of saidouter wedges,

a is the radial offset from the axis of the center of said curvedinclined wedge surfaces which are eccentric to the axis,

,a is the coefiicient of sliding friction on said curved inclined wedgesurfaces which are eccentric to the axis,

1', is the radius of curvature of said inner cylindrical coaxial wedgesurface,

r is the radius of curvature of said outer cylindrical coaxial wedgesurface,

r is the mean radius of curvature of said cylindrical inclined wedgesurfaces which are eccentric with respect to the axis of hub rotation,

and positive pre-engaging means for producing limited relative motion ofthe outer and inner wedges in a direction toward inclination of theinclined wedge surfaces (tightening) for engaging and pre-tightening ofthe wedge elements against the concentric surface on the hub member, andthe concentric surface of the shaft member, whereby said wedges producea self-interlocking action at said external and internal cylindricalcoaxial surfaces in the direction toward the inclination of the inclinedwedge surfaces, which is also self-releasing and complies with thefollowing condition:

a r .t

said wedges of each pair also have inclined wedge surfaces when viewedin axial section.

2. A wedge device of claim 1, in combination with positive rigid meansused for pre-engagement to produce axial relative limited motion on theinclined surfaces for tightening the wedges.

3. A rotary self-interlocking wedge device, comprising a shaft member, ahub member surrounding the shaft member and having a space of annularsection between the shaft member and the hub member, the members beingrelatively angularly movable about a common axis of the shaft member andthe hub member, pairs of cooperating wedges between the shaft member andthe hub member on opposite sides, each pair of wedges comprising aradially inner wedge having a radially inner cylindrical surface coaxialwith said common axis and cooperating with the outer cylindrical surfaceof said shaft member, and having a radially outer curved inclined wedgesurface whose section is circular and which is eccentric with respect tothe axis, and comprising a radially outer wedge having a radially innercurved inclined wedge surface whose section is circular and which iseccentric with respect to the axis and of the same radial offset as theradially outer inclined wedge surface of the inner wedge of the pair,the inclined wedge surface of the outer wedge of each pair being insliding frictional engagement with the inclined wedge surface of theinner wedge of the same pair, there being permanent anti-friction meanson at least one of the inclined wedge surfaces which are in slidingengagement, and the radially outer wedge of each pair having a radiallyouter cylindrical surface coaxial with said common axis and cooperatingwith the inner cylindrical surface of said hub member, each of saidpairs of wedges having the same direction of inclination of the inclinedsurfaces relatively tightening when rotation is in the direction towardinclination of the inclined wedge surfaces and each of said pairs ofwedges which have said same direction of inclination of the inclinedwedge surfaces rela-' tively loosening when the rotation is in thedirection away from the inclination of the inclined wedge surfaces, saidwedge device complying with the following conditions:

12 where f is the coefficient of sliding starting friction on thecoaxial cylindrical surface of said inner wedges,

f is the coefiicient of sliding starting friction on the coaxialcylindrical surfaces of said outer wedges,

a is the radial offset from the axis of the center of said curvedinclined wedge surfaces which are eccentric to the axis,

[L is the coefficient of sliding friction on said curved inclined wedgesurfaces which are eccentric to the axis,

r is the radius of curvature of said inner cylindrical coaxial wedgesurfaces,

r is the radius of curvature of said outer cylindrical coaxial wedgesurface,

1' is the mean radius of curvature of said cylindrical inclined wedgesurfaces which are eccentric with respect to the axis of hub rotation,

and positive pre-engaging means for producing limited relative motion ofthe outer and inner wedges in a direction toward inclination of theinclined wedge surfaces (tightening) for engaging and pre-tightening ofthe wedge elements against the concentric surface on the hub member, andthe concentric surface of the shaft member, whereby said wedges producea self-interlocking action at said external and internal cylindricalcoaxial surfaces in the direction toward the inclination of the inclinedwedge surfaces, in which said wedges of each pair also have inclinedwedge surfaces when viewed in axial section.

4. A rotary self-interlocking wedge device, comprising a shaft member; ahub member surrounding the shaft member and having a space of annularsection between the shaft member and the hub member, the members beingrelatively angularly movable about a common axis of the shaft member andthe hub member, pairs of cooperating wedges between the shaft member andthe hub member on opposite sides, each pair of wedges comprising aradially inner wedge having a radially inner cylindrical surface coaxialwith said common axis and cooperating with the outer cylindrical surfaceof said shaft member, and having a radially outer carved inclined wedgesurface whose section is circular and which is eccentric with respect tothe axis, and comprising a radially outer wedge having a radially innercurved inclined wedge surface whose section is circular and which iseccentric with respect to the axis and of the same radial offset as theradially outer inclined wedge surface of the inner wedge of the pair,the inclined wedge surface of the outer wedge of each pair being insliding frictional engagement with the inclined wedge surface of theinner wedge of the same pair, there being permanent antifriction meanson at least one of the inclined wedge surfaces which are in slidingengagement, and the radially outer wedge of each pair having a radiallyouter cylindrical surface coaxial with said common axis and cooperatingwith the inner cylindrical surface of said hub member, each of saidpairs of wedges having the same direction of inclination of the inclinedsurfaces relatively tightening when rotation is in the direction towardinclination of the inclined wedge surfaces and each of said pairs ofwedges which have said same direction of inclination of the inclinedwedge surfaces relatively loosening when the rotation is in thedirection away from the inclination of the inclined wedge surfaces, andpositive pre-engaging means for producing limited relative motion of theouter and inner wedges in a direction toward inclination of the inclinedwedge surfaces (tightening) for engaging and pre-tightening of the wedgeelements against the concentric surface on the hub member, and theconcentric surface of the shaft member, whereby said wedges produce aself-interlocking action at said external and internal cylindricalcoaxial surfaces in the direction toward the inclination of the inclinedwedge 13 14 surfaces, said inclined wedge surface of each wedge of2,785,782 3/1957 Dodge 192-45.1 each pair also being inclined whenviewed in axial section. 3,107,764 10/ 1963 Fulton 192-41 ReferencesCited FOREIGN PATENTS UNITED STATES PATENTS 5 58,276 12/1940 Denmark.

Dana France. 3/1917 Phillips 28752.09 1,088,396 9/1954 Franc 3/1939 DeFalco 192 45'1 293,122 7/1928 Great Bntaln. 2x328 06 10 CARL W. TOMLIN,Primary Examiner. 5/1951 Rudolph 287 52,06 ANDREW KUNDRAT, AssistantExaminer.

4. A ROTARY SELF-INTERLOCKING WEDGE DEVICE, COMPRISING A SHAFT MEMBER, AHUB MEMBER SURROUNDING THE SHAFT MEMBER AND HAVING A SPACE OF ANNULARSECTION BETWEEN THE SHAFT MEMBER AND THE HUB MEMBER, THE MEMBERS BEINGRELATIVELY ANGULARLY MOVABLE ABOUT A COMMON AXIS OF THE SHAFT MEMBER ANDTHE HUB MEMBER, PAIRS OF COOPERATING WEDGES BETWEEN THE SHAFT MEMBER ANDTHE HUB MEMBER ON OPPOSITE SIDES, EACH PAIR OF WEDGES COMPRISING ARADIALLY INNER WEDGE HAVING A RADIALLY INNER CYLINDRICAL SURFACE COAXIALWITH SAID COMMON AXIS AND COOPERATING WITH THE OUTER CYLINDRICAL SURFACEOF SAID SHAFT MEMBER, AND HAVING A RADIALLY OUTER CURVED INCLINED WEDGESURFACE WHOSE SECTION IS CIRCULAR AND WHICH IS ECCENTRIC WITH RESPECT TOTHE AXIS, AND COMPRISING A RADIALLY OUTER WEDGE HAVING A RADIALLY INNERCURVED INCLINED WEDGE SURFACE WHOSE SECTION IS CIRCULAR AND WHICH ISECCENTRIC WITH RESPECT TO THE AXIS AND OF THE SAME RADIAL OFFSET AS THERADIALLY OUTER INCLINED WEDGE SURFACE OF THE INNER WEDGE OF THE PAIR,THE INCLINED WEDGE SURFACE OF THE OUTER WEDGE OF EACH PAIR BEING INSLIDING FRICTIONAL ENGAGEMENT WITH THE INCLINED WEDGE SURFACE OF THEINNER WEDGE OF THE SAME PAIR, THERE BEING INCLINED WEDGE SURFRICTIONMEANS ON AT LEAST ONE OF THE INCLINED WEDGE SURFACES WHICH ARE INSLIDING ENGAGEMENT, AND THE RADIALLY OUTER WEDGE OF EACH PAIR HAVING ARADIALLY OUTER CYLINDRICAL SURFACE COAXIAL WITH SAID COMMON AXIS ANDCOOPERATING WITH THE INNER CYLINDRICAL SURFACE OF SAID HUB